An escape respirator filter device with a respirator filter on the respirator connection, in which the respirator filter is connected to a mask body via bellows, has become known from West German Patent Specification No. DE-PS 32,36,028. The bellows seal off the interior space of the mask against the surrounding atmosphere and surround the respirator filter at the filter outlet in the form of a rigid cuff. Since the cuff has to assume holding and sealing functions at the same time, it is designed as a clip laid around the bellows. The respirator filter is arranged displaceably over the bellows in the mask body. A guide ring, whose diameter is such that the respirator filter can be pushed through with ease, is fastened on the mask body at the passage opening of the respirator filter. The bellows follow the axial displacement of the respirator filter. The stroke length is limited by the rigid cuff striking the guide ring.
It is a disadvantage of this prior-art escape respirator filter device that in order to change the respirator filter, the cuff must be taken apart by removing the clip from the bellows. This is time-consuming, because the removal must be performed in the poorly accessible interior space of the mask, and a tool is also needed to detach the clip.
West German Utility Patent No. DE-GM 67,52,895 discloses a respirator mask, which is made of an elastic plastic, and in the area of the respirator connection, it has a bellows-like projection, into which a respirator filter is inserted. Within the bellows-like projection, the respirator filter is fixed by a surrounding collar on the filter inlet and by a stop on the filter outlet.
It is a disadvantage of the prior-art device that it is difficult to remove the respirator filter from the bellows-like projection, because no dimensionally stable, cylindrical holder is provided at the filter outlet, and the bellows-like projection must be folded over the entire length of the filter when removing the respirator filter. In addition, there is no possibility of fixing a folded-over section of the bellows-like projection.